1. Field of the Invention
The invention relates to plug on devices used to bidirectionally communicate with a control unit of a vehicle. More particularly, the invention relates to a calibration tool assembly that is capable of measuring all measurement variables from a control unit of a vehicle in real time to identify opportunities to enhance performance, and to identify and debug issues.
2. Description of the Related Art
Modern electronic control units (ECUs) include engine electronic control units and transmission electronic control units, and will hereinafter be referred to as ECUs. ECUs are highly complex systems that implement a plurality of real-time control algorithms within a single microcontroller. To aid in the development and testing of these real-time control algorithms, it is sometimes necessary to connect a Plug On Device (POD) to a microcontroller debug interface, which provides real-time access to the microcontrollers memory. Developers are able to perform high speed data acquisition (DAQ) to observe the control algorithms, high speed data stimulation (STIM) to replace algorithm outputs partly or even completely with outputs of different algorithms that are calculated on an external high-speed system (called bypassing), or to calibrate control algorithm parameters (CAL) while the systems being operated by the ECU is running.
PODS are connected to a single or multiple microcontroller debug interfaces to access the memory of the microcontroller asynchronously. In most cases, it is therefore necessary to integrate a small piece of service code into the ECU software that ensures data consistency and time alignment when performing DAQ and STIM, as well as providing additional features for parameter calibration and bypass status detection.